The present invention relates, in general, to hermetic compressors and, more particularly, to an apparatus for depreciating a noise of highly compressed working fluid in such hermetic compressors.
FIG. 1 shows the internal construction of a conventional hermetic compressor having a connecting rod.
As shown in the drawing, the conventional hermetic compressor comprises a hermetic housing 1 consisting of upper and lower casings 1t and 1b, with a sealed cavity being formed within the housing 1 and a frame 2 being set within the sealed cavity of the housing 1. A stator 3 is fixedly mounted to the frame 2 and electromagnetically rotates a rotor 4 integrated with a crankshaft 5, thus finally rotating the crankshaft 5. The construction of the rotor 4 will be described in detail later herein. The above frame 2 is held in the hermetic housing 1 by a spring 2S.
The crankshaft 5 is installed within the hermetic housing 1 while passing through the central portion of the frame 2, while the rotor 4 is integrated with the crankshaft 5 into a single structure. The above rotor 4 is electromagnetically rotated along with the crankshaft 5 in cooperation with the stator 3.
An eccentric pin 5b is provided on the upper end of the crankshaft 5 while being eccentric from the rotating axis of the crankshaft 5. A balance weight 5c is provided on the crankshaft 5 at a position opposite to the eccentric pin 5b. Provided on the lower end of the crankshaft 5 is a pump 5d, which generates pumping force for sucking lubrication oil L from the bottom of the lower casing 1b of the housing 1 to an oil passage 5a of the crankshaft 5.
On the other hand, a cylinder 6, having a compression chamber 6xe2x80x2, is integrated with the frame 2 into a single structure, with a piston 7 being set in the compression chamber 6xe2x80x2 of the cylinder 6. The above piston 7 is connected to the eccentric pin 5b of the crankshaft 5 through a connecting rod 8. In such a case, the eccentric pin 5b of the crankshaft 5 is connected to a crankshaft connection part 8a of the connecting rod 8, while the piston 7 is connected to a piston connection part 8b of the connecting rod 8 through a piston pin 7xe2x80x2.
A valve assembly 9 is installed on the end of the cylinder 6. This valve assembly 9 controls a flowing of working fluid, or refrigerant, which is sucked into and exhausted from the compression chamber 6xe2x80x2 of the cylinder 6. A head cover 10 is mounted to the valve assembly 9 so as to form an exhaust chamber 10xe2x80x2 (see FIG. 3), through which the working fluid passes after being exhausted from the compression chamber 6xe2x80x2. In the drawing, the reference numeral 12 denotes a suction pipe used for sucking the working fluid into the hermetic housing 1, and the reference numeral 13 denotes an exhaust pipe used for discharging the compressed working fluid from the compressor into the outside of the compressor.
In the above compressor, a suction muffler 11 is installed within the hermetic housing 1 while communicating with the compression chamber 6xe2x80x2 of the cylinder 6 through the valve assembly 9. The above suction member 11 is used for educing operational noises of the working fluid.
The above compressor also has a device for muffling exhaust operational noises of compressed and exhausted working fluid during an operation of the compressors. The construction of this muffling device is shown in FIGS. 2 to 4. As shown in the drawings, a fluid exhaust passage 14 is formed in the compressor while passing through the cylinder 6 and communicates with the exhaust chamber 10xe2x80x2 formed by the head cover 10. A muffling unit 16 is formed on the frame 2 and receives the working fluid flowing from the exhaust passage 14. A chamber cover 17 is mounted to the frame 2, thus defining a muffling chamber 16xe2x80x2 of the muffling unit 16. The exhaust operational noises of the compressed working fluid is practically reduced within the muffling chamber 16xe2x80x2. A loop pipe 18 is installed on the muffling unit 16 while passing through the chamber cover 17.
In the above muffling unit 16, the chamber cover 17 is locked to the frame 2 by a locking bolt 19, thus forming the desired muffling chamber 16xe2x80x2 of the muffling unit 16. The above locking bolt 19 is tightened to the locking boss 16b formed on the frame 2. A diaphragm 21 is installed within the muffling chamber 16xe2x80x2 of the muffling unit 16 so as to divide the muffling chamber 16xe2x80x2 into two parts. The object of such a division of the muffling chamber 16xe2x80x2 by the diaphragm 21 is to improve the noise-muffling effect of the muffling unit 16.
The above diaphragm 21 has a hole 22 at its center, thus allowing the two parts of the muffling chamber 16xe2x80x2 to communicate with each other through the hole 22. The above hole 22 also allows the locking bolt 19 to pass through prior to being tightened to the locking boss 16b of the frame 2. The diaphragm 21 is thus locked to the frame 2 along with the chamber cover 17 by the locking bolt 19.
In order to prevent a leakage of working fluid from the muffling chamber 16xe2x80x2 of the unit 16, two packing rings 20 and 20xe2x80x2 are closely interposed between the frame 2, the chamber cover 17 and the upper and lower surfaces of the edge of the diaphragm 21 as best seen in FIG. 4. A sealing washer 19xe2x80x2 is fitted over the shank of the locking bolt 19, thus being closely positioned at the junction between the bolt head and the top center of the chamber cover 17 and sealing the junction when the bolt 19 is fully tightened to the locking boss 16b of the frame 2 along with the chamber cover 17.
In an operation of the above hermetic compressor, compressed working fluid is discharged from the compression chamber 6xe2x80x2 of the cylinder 6 as follows. That is, the working fluid, compressed by the piston 7 within the compression chamber 6xe2x80x2, is discharged from the chamber 6xe2x80x2 into the exhaust chamber 10xe2x80x2, formed by the head cover 10, through the valve assembly 9, used as an exhaust valve.
The compressed working fluid is, thereafter, fed to the muffling chamber 16xe2x80x2 through the fluid exhaust passage 14 formed in the cylinder 6. In the muffling chamber 16xe2x80x2, the working fluid orderly passes through the two parts of the chamber 16xe2x80x2, thus being reduced in pulse of pressure wave prior to being discharged from the muffling chamber 16xe2x80x2 into the outside of the hermetic housing 1 through the loop pipe 18.
However, the conventional apparatus for noise depreciating of compressed working fluid in a hermetic compressor is problematic as follows due to the fact that it is somewhat difficult to lock both the chamber cover 17 and the diaphragm 21 to the locking boss of the frame using the locking bolt 19, thus reducing work efficiency while forming a desired apparatus for depreciating noises in the compressor.
That is, in order to mount both the chamber cover 17 and the diaphragm 21 to the frame 2, the first packing ring 20xe2x80x2 is laid on the frame 2 at a position around the muffling unit 16 prior to laying the diaphragm 21 on the packing ring 20xe2x80x2. Thereafter, the second packing ring 20 is laid on the edge of the diaphragm 21 prior to laying the chamber cover 17 on said packing ring 20. The chamber cover 17 is, thereafter, fully locked to the locking boss 16b of the frame 2 by the locking bolt 19 along with the diaphragm 21 and the two packing rings 20 and 20xe2x80x2.
However, it is very difficult to precisely array the chamber cover 17, the two packing rings 20 and 20xe2x80x2 and the diaphragm 21 with each other or to keep the primarily arrayed positions of them on the frame 2 while assembling them with the frame 2 using the locking bolt 19. Therefore, they may fail to be precisely assembled to each other on the frame 2. The conventional apparatus for noise depreciating for hermetic compressors is thus undesirably reduced in work efficiency while being assembled into a single structure.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an apparatus for noise depreciating of highly compressed working fluid in hermetic compressors, which is designed to improve work efficiency while being assembled into a desired single structure.
In order to accomplish the above object, the present invention provides an apparatus for noise depreciating in hermetic compressors, comprising: a muffling chamber adapted for reducing noises of compressed and exhausted working fluid prior to discharging the working fluid from a compressor, a chamber cover adapted for sealing the muffling chamber from the outside of the chamber, a means for dividing the muffling chamber into two or more parts and being integrated with the chamber cover into a single body, and a means for locking the chamber cover to a frame of the compressor so as to allow the chamber cover to seal the muffling chamber.
In the above device, the muffling chamber dividing means is welded to a step formed on the internal surface of the chamber cover. This dividing means also has a dome shape, with an inclined part being formed along the edge of the dome-shaped dividing means so as to allow a process of welding the dividing means to the chamber cover to be easily performed.
In the apparatus for noise depreciating of this invention, the number of parts is preferably reduced, and so it is possible to remarkably improve work efficiency and productivity while assembling such muffling devices.